the actual weight diff comes out to 4 grams extra for each mds lifter.

steve

Good info, Gremlinsteve, Can you email me with info of your business? Looking for cams and internal parts.

The MDS system uses different lifters from the 6.1L. You must use the 6.1 lifter with the 6.1L cam. All you have to do is disconnect the connecters on the deactivation solinoids to disable the MDS system. I remember seeing a company that was making port plugs for MDS blocks at SEMA but never grabbed any info.

or 5.7 truck lifters. all together the parts from mopar only run about 250$$$ thats with the head gaskets and bolts to go with it.

now, b&g can take the lx platforms computer and tune the mds out of it which isnt a bad thing either that way you get rid of all the little check lights and cel's that might pop up. i do not think that a mds cel will alter the way the car runs as some of the codes do.

steve-o

Sharadon.............not meaning to argue, just telling what we know.

Your statement was "will not tollerate"...........all we were doing is letting you know that wasn't true. Where the "spring" part of this conversation came from is beyond me.

MDS works fine in the .500 - .530 area.............some guys have MDS kicking in at 80-90 mph going down the freeway...........all thru efficiency; crazy stuff.

We do NOT advocate the use of the MDS period..........more, small moving parts that add to valve train weight.................but it does work over .500.

it does run better with the comp 918 tho.

This is were I got the spring statement from. I'm not trying to argue either just stating my opinion.

My statement (will not tolerate) Yes, I should have stated it differently. But If the valve train isn't operating properly your headed for trouble. So if you are using a bigger then stock cam why would you use stock springs or a MDS lifter. I don't.

Can it be done, sure it can. A lot of thing can be done that should'nt.

Just my opinion

not our test. i was just passing on info from some one in the country that actually tested the 260 comp with the stock spring. he drove the car for several weeks/months with the stock spring and stated that it ran fine.

he did upgrade to a comp 918 after that test and stated that the car did pick up some et at the track.

i would have done the spring and cam swap at the same time.

a 5.7 spring has about 86 lbs of seat. i forget the open pressure.

6.1 was about 100 if i remember right. maybe a 110. ill have to go back and look at my notes for that. it would be a cheaper upgrade in spring tho on the head.
even the ls6 gm spring will work. you will have to shorten the install height to a 1.750 tho to get seat pressure up a tad more.

steve

The cheap popular spring is the 6.1 exhaust spring. It's 130 on the seat and 330 open. The manley spring is 130 on the seat and 360 open. I think the comp spring is 125/300. They all work without issue. I never bothered to check the 5.7 spring.

Ok, well say i leave the MDS alone and JUST replace the lifters and cam with the 6.1 cam i priced for $130 at the dodge dealership. Shouldn't it be just fine?? And, what is the lift on the 6.1 cam?

no it won't be enough.............change the springs. Lift is in the 330-ish range

I have all the specs but not on me right this second................I'll look up later for you.

Lift at the valve is .540 Some have kept their 5.7 springs using the 6.1 cam. I don't recommend doing that. Sooner or later the 5.7 spring will fail. Not worth the gamble. Try to buy 2 sets of 6.1 exhaust springs. Or get the Manley springs.

You still have to deal with the MDS in the pcm.